There’s no such thing as bad publicity, they say, but what about when your brand is associated with a tragic news event involving torture, rape, and kidnapping?

That is the situation now facing McDonald’s, the fast-food burger chain that was name-dropped incessantly in the media after last week’s rescue of Michelle Knight, Gina DeJesus, and Amanda Berry from a Cleveland house where police say they were captive for 10 years. Charles Ramsey, a neighbor who rescued Ms. Berry and first alerted police, became an online folk hero when videos of him went viral.

Not only did Mr. Ramsey deliver colorful one-liners that instantly became fodder for meme creators, but, in describing how he happened upon Berry’s cries for help, he continually reminded interviewers he heard them when he was just minding his own business and enjoying a meal from – you guessed it – McDonald’s.

McDonald’s heard the call and last week issued a tweet telling Ramsey “way to go” and “we’ll be in touch.” The company followed up with a press release, saying it would “personally be reaching out to Mr. Ramsey directly as we said we would.”

When choosing to become involved in an international news event that involved such horror – Ariel Castro is charged with three counts of rape and four counts of kidnapping in the case – is there a good time or a bad time for a company to extend a helping hand?

To some brand marketers, it depends on the situation. Oreo, for example, earned raves after it swiftly sent a tweet in the moment following a blackout during the Super Bowl in New Orleans. It told followers: “You can still dunk in the dark.”

Other brands that were suddenly thrust into the national conversation this past year include Skechers (the boots a New York City police officer was photographed handing a homeless person in Times Square), Poland Spring (the water brand Marco Rubio reached for during his Republican rebuttal to the president's State of the Union speech), Skittles and Arizona Iced Tea (the items Trayvon Martin bought at a convenience store before his fatal confrontation with George Zimmerman), and Big Bird (name-checked by Mitt Romney during a presidential debate).

In all these cases, the companies were forced to respond in ways especially tailored to the situation. For example, after the Internet exploded with people’s admiration of police officer Larry DePrimo’s generosity in helping the homeless man stay warm with a pair of their boots, Skechers announced it was donating 50 pairs of insulated boots to a homeless shelter.

In the case of Ramsey, the Cleveland man should receive some kind of compensation from McDonald’s, especially since the company made the public commitment to establish some kind of relationship, experts say.

“When a multinational corporation makes a commitment, it has to follow through,” says Karen Mishra, an associate professor of marketing at the Meredith College School of Business in Raleigh, N.C.

One suggestion: offer him a job at a local McDonald’s.

“I'm sure that they wanted to capitalize on the moment … but when you make a hasty decision without knowing exactly who is involved, just because they say they are using your product, you commit yourself, your company, and your brand, no matter what,” Professor Mishra says.

Ramsey, it turns out, was convicted of domestic violence three times from 1997 to 2003 and served time in jail – though supporters note that was a decade ago.

Others say the company might bypass Ramsey and promote a charitable cause directed to the victims.

“If McDonald’s wants to ride the social media publicity wave, it could make a seed donation to a fund that will help pay for some of the medical care and psychiatric treatment these victims will need so they can reenter society and live normal lives,” says Mark Tatge, a professor at DePauw University’s Center for Contemporary Media in Greencastle, Ind.

In the end, “the extremely sensitive nature of the case, the fleeting and flighty nature of instant fame, and the under-the-surface vagaries of Charles” might mean it’s not a good idea for McDonald’s to become involved at all, says Chas Withers, president of Dix & Eaton, a branding firm in Cleveland.

“While not directly ‘exploitative,’ it doesn't necessarily feel true to McDonald's principles and values and is short-term thinking that might include more risk than reward,” Mr. Withers says.

After all, another person involved in the case enjoyed McDonald’s cuisine the same day as Ramsey: Mr. Castro. Police made their arrest as he sat in his car in a McDonald’s parking lot. His brothers also reported that, at least on one occasion, Castro took the 6-year-old girl he had with Berry to a McDonald’s restaurant and told people she was the daughter of his girlfriend.

“Brands do indeed walk a fine line when they consider possible celebrity endorsers, even if they are only famous for the proverbial 15 minutes,” says Ronald Hill, a professor at the Villanova School of Business Marketing in Philadelphia. “Once a firm makes the connection, there is no going back. In fact, whatever positive synergy that might have occurred can be lost when the larger media makes a big deal out of a poor decision to link arms.”